Refrigerating apparatus



Feb. 2, 1943. D. E. DASHER 2,309,756

REFRIGERATING APPARATUS l Filed Nov. 25, 1938 2 Sheets-Sheet l 3 fi /4% A 4 fa #8- I 40 I 9 2/0 INVENTOR.

g STRONG LIQUOR BY -WERK LIQUOR C AMMON n %,o4/ W ATTORNEYSM REFRIGERATING' APPARATUS Filed Nov. 25, 1938 2 Sheets-Sheet 2 r INVENTOR.

%Z4V ATTORNEYS Patented Feb. 2, 1943 REFRIGERATING APPARATUS Don E. Dasher, Dayton, Ohio, assignor: to Gen- 7 eral Motors Corporation, Dayton, Ohio, a corporation 01' Delaware Application November 25, 1938, Serial No. 242,177 15 Claims. (01. 62-5) This invention relates to refrigerating appa- ."ratus and more particularly. toabsorptionrefrigerating systems employing a liquidabsorbent.

It is an object of my invention to provide a I liquidabsorbent refrigerating system not requiring a pressure equalizing gas or pumps which will provide substantially continuous refrigeration.

It is another object of my invention to provide a continuous multi-gpressure liquid absorption system without valves inthe-refrigerant circuit.

It is another object of my I invention to provide a twin liquid absorption system in which the weak liquor is fed from one portion of the systemtoanother. I

It is another object of my invention to provide a liquid absorption system in which the condenser is also used as an absorber.

It is another object of my invention to provide a liquid absorption system without valves in which the absorption of therefrigerant in the weak liquor takes place by counter-flow of the weak liquor and the evaporated refrigerant.

It is another object of my invention to provide in a liquid absorption system, a generatin means provided with a counter flow heating arrangement.

It is another object of my invention to provide an absorption system with a manually initiable defrosting device which automatically returns the system to normal temperature at the completlon of the defrosting.

It is still another object of my invention to provide a control for an absorption refrigerating system which is responsive individually to evaporator temperature and the temperature or the. compartment cooled by the evaporator.

Further objects and advantages of the present invention will be apparent from the following sorption machine having a series type of evaporating means which is divided into two portions, each portion being connected to a condenser which, in turn, is connected to a generator. A

restrictor is provided between the two portions;

of the evaporating means and weak liquor conduits are provided for conducting weak liquor from each generator to the top of the condenser V. A restrictor connected to the other generator. is Placed in these weak liquor conduits in order to control the flow of weak liquor fror'n'the one generator to the condenser connected to the other generator. A thermostat is'provided for swinging the burner so as to supply heat to one of the generators at a time, and for changing the supply of heat at the proper time from one generator to another. A thermostatic valve is provided for controlling the flow of gas to the burner according to evaporator, and compartment temperatures. This valve is provided with a semi automatic defrosting'device. i

The sitstem Referring now particularly to Fig. 1, there is shown a primary evaporating means having a portion 20 and another portion 22 which are divided by a restrictor 24. These two evaporatin portions 20 and 22 are in heat exchange relation with the containers 26 and 28 which. together with the refrigerant portions 20 and 22 and the restrictor 24, are "surrounded by insulating means. These containers 26 and 28 are connected by drain conduits 30 and 32 120 a seconda'ry evaporating means 34 containing a vola- A tile liquid. Thesecondary evaporating means 34 is located in the compartment 38 to be cooled.

. The secondary evaporating means 34 is provided description, reference being had to the accompanying drawings. wherein a preferred form of the present invention is clearly shown.

In the drawings:

Fig. l is'a view partly diagrammatic and partly sectional of an entire twin type liquid absorption system embodying my invention;

' Fig. 2 is a sectional view of the burner conwith shelves upo'n'which may be frozen water in ice trays. The secondary evaporating means 34 is partially filled with the volatile liquid and the volatile liquid within the secondary evaporating means evaporates because of the absorption of heat in the air of the compartment and this vapor passes upwardly thro h one of the tubes or conduits 30 or 32 into one of the chambers 28 or 28 where it is condensed and 'retumed to the secondary evaporator I4 by the same path.

The primary evaporating means 22 is connectedby the conduit 30 to a heat exchange portion 4| which, in turn, is connected to strap 42 located at the bottom of the condenser 44. The top of the condenser 44 is also provided with a chamber 4! which. in turn, is connected by the conduit 4| to the top of the reservoir portion II or the one generator. A drain it is also provided connecting the trap 42 with the lower portion of the reservoir ill.

The reservoir 50 is provided with a connection to an interchanger 5| which has its other end connected to the bottom of the jacket surrounding the generator heating flue 56. The top of the jacket surrounding the generator heating flue I is connected by a conduit 5| with the upper portion of the reservoir 50. The bottom of the jacket surrounding the generator flue II is provided with connecting conduit 60 which connects to the outer jacket of the interchanger I4 having its other end connected by a conduit 82 to a restrictor 6| which, in turn, is connected by a conduit 56 with the container I provided above the second condenser I.

This second portion of the system is substantially identical to the first portion of the system and its respective parts are provided with reference characters I00 higher than the reference characters applied to corresponding parts of the Operation The arrows indicate the direction of flow of strongand weak liquor and ammonia when the generator 82 is being heated. In operation, when the heating of the one generator starts, it is substantially filled withrich liquor while the other generator is substantially empty. The portion in the jacket surrounding the generator heating flue Iii is heated the most and the refrigerant is driven out of the liquor by the heat and passes upwardly out of the rear end of the jacket into the conduit 58 which extends .upwardly and discharges into the upper portion of the reservoir portion 50 above the liquid level. This refrigerant in vapor form thence passes upwardly through the conduit 48 to the container 46 and thence flows downwardly through the condenser This refrigerant condenses in the condenser 44 and drains into a liquidtrap 42 from which liquid refrigerant flows upwardly through the conduit 4|] which is in heat exchange relation with the conduit Ill], and thence the liquid refrigerant flows through the conduit 38 to the primary evaporating portion 22. The liquid refrigerant, however, does not evaporate until it passes through the restrictor 24 and reaches the other evaporating portion 20 where it evaporates under reduced pressure and condenses the volatile secondary liquid in the container 26. The vaporized volatile secondary liquid is thus condensed and returned to the evaporating means in this manner. The primary evaporating portion 22 supplies little or no heat to the volatile secondary liquid because the container 28 contains only vapor and the heating of this vapor will prevent any substantialamount of circulation between the condenser 28 at this time and the evaporating means 34. The liquid refrigerant in the primary system evaporates within the evaporating portion 20 and is conducted downwardly through conduit I38 to a conduit I" which is in heat exchange relation with the conduit 40 and thus the refrigerant vapor in the conduit I40 absorbs the heat of liquid from the liquid refrigerant flowing through the conduit 40 by counterflow heat transfer.

This conduit ilii connects to the liquid trap H2 at the bottom of the condenser I. This refrigerant vapor then flows upwardly through the condenser I, while the weak liquor flows from the conduit 66 into the container I46 and thence downwardly through the condenser i to meet the upward flowing refrigerant vapor. In this way, the weak liquor is cooled in the upper portion of the condenser and in the lower portion absorbs the ascending refrigerant vapor in a counter-flow absorption arrangement so that this weak liquor now becomes fully enriohed and collects in the liquid trap 14: from which it is drained through the drain conduit I52 which connects to the lower portion of the reservoir portion I50 of the other generator. In

this way, the second generator is gradually filled with fully enriched liquor during the heating of the other generator.

It should be noted that the weak liquor from the generator being heated is taken from the front end of the jacket surrounding the heating fiue 56 at which'the temperature is the highest and the liquor is the weakest. This hot weak liquor thence flows through the conduit 80 to the lower end of the outer jacket of the heat interchanger 54 and exchanges its heat by counterflow heat. transfer with the rich liquor which flows from the bottom of the reservoir portion II through the inside of the heat exchanger 54 to the lower portion of the rear end of the Jacket surrounding the heating flue 56. This cools the weak liquorconsiderably and the weak liquor is further cooled in the conduit 52, the restrictor 64 and the conduit 86 before it reaches the container H6 at the top of the second condenser I.

The restrictor 64 controls the flow of weak liquor from the .jacket surrounding the heating flue 56 in accordance with the pressure differential existing between the different portions of the system and, likewise, the refrigerant flows through the restrictor 24 in accordance with the pressure differential existing between the different portions of the system. Thus, the flow of refrigerant from the generating side to the absorption side is controlled by the same factors which control the flow of weak liquor from the generating side to the absorption side. In this way, by properly proportioning the restrictors 24, I and I, the rate of fiow of refrigerant and weak liquor may be correctly proportioned to insure the greatest efliciency.

The contents of the reservoir portion is gradually reduced by the passing of the refrigerant vapor into the condenser 44 and by the passing of the weak liquor into the condenser I upon the absorption side of the system. When substantially all of the liquid is drained from the reservoir iii and the liquid level in the jacket surrounding the' heating flue it begins to fall, the temperature of a thermostat I! mounted upon the top of the front portion of the Jacket becomes sufliciently high to throw the swinging burner 68 from the full line'position shown in Fig. 1 to the dotted line position. This is done by a mechanism generally designated by the reference character 18 and better shown in Figs. 2 and 3. This mechanism I8 is connected to a thermostat bulb 16 by capillary tubing ltand is Thus, when the one generator 82 is substantially drained of liquor, the other generator I82 is substantially filled with rich liquor, the thermostats 18 and 118 thence cause thebumer 88 to swing from the flue 58 to the flue I58 in order to reverse the system. This reversal causes refrigerant in vapor form to be separated from the liquor in the generator I82 and to pass upwardly through the conduit I48 to, the container-l48 and thence to be condensed in theboridenser I44, after which it passes upwardly through theconduits I48, I88 and the primary evaporating portion 28 to the restrictor'24 which controls the flow of liquid refrigerant to the primaryevaporating portion 22 where the liquid refrigerant evaporates and cools the container 28. The vapor from the secondary volatile liquid condenses in the container 28 to keep the evaporator 84 at the proper temperature.

The refrigerant evaporated in the evaporating portion 22 passes through, the conduits 88 and,

48 to the bottom of the condenser 44, while weak liquor from the generator I82 flows through the conduit I82 under the control'oi the restrictor I84 to the conduit I88 which conducts the weak liquor to the container 48 at the top of the condenser 44. This weak liquor is cooled in the top of the condenser 44 and meets and absorbs the evaporated refrigerant rising in the condenser and absorbsthe refrigerant vapor infcounter-fiow fashion. This enriches the weak liquor and the enriched weak liquor then flows into and gradually fills the generator 82.

. The liquid absorbent may be water, and the re-' frigerant may be ammonia or one of the sets v of liquid absorbents and refrigerants mentioned in the Fleischer Patent No. 2,035,541 may be used.

The thermostatic throttling valve The evaporating means 84 is kept atthe proper temperature by a throttling valve 2I8 located in series with the gas supply conduit 2I2 which through the conduit 2I4 feeds the swinging Bunsen-type burner 88. This throttling valve opens in accordance with the temperatures of two thermostat bulbs. One of the bulbs 2I8 is located in heat exchange relation with the evaporating means 84 and the other2l8 is located in heat exchange relation with the air in the compartment 38. These bulbs are each connected by capillary tubing 228 and 222 to the throttlin valve 2 I 8.

either a high evaporating temperature or a high compartment temperature and conversely; the valve tends to close under either a low evaporator temperature or low compartment temperature conditions. 7

Referring now more particularly to Fig. 4 for a detailed disclosure of the throttling valve M8, the 75 214.

common capillary tube 224 connects at one end to thecaplllary tubes 228 and 222- and at the opposite side of the shaped member 248 other end is connected to a threaded plug 228 which extends into the valve casing 228and has ,a bellows 288 connected at'its inner end. This I plug 228 may be turned to move the bellows 288 inwardly 'or outwardly to adjust the position of the bellows. The threaded plug 228 is provided with a drilled aperture which'at one end connects with the interior of the capillary tubing 224 and at the other end communicates with the interior of the bellows 288.

Within the bellows 288, there is provided a bellows stop 282 which cooperates with a head upon the valve stem 284 to prevent excessive expansion of the bellows 288. The one end 01 the bellows 288 is fastened to a bellows stop'282 and to the threaded plug 228, while the opposite end is connected to an end plug which is soldered to the valve stem 284. The valve stem 284 at its opposite end carries a valve 288 for closing the valve opening in the dividing wall 288. The dividing wall 288 is also provided with a small-aperture 248 which allows a small amount or gas to fiow from one side of the wall to the other, even when the valve 288 is closed, in order to prevent the gas burner from going out when the temperatures within the evaporating means and the compartment to be cooled are low. The valve body 228 is provided with an inlet connecting fitting 242 tor connecting with the suppl pipe 2I2 and is provided with'an outlet fitting 244 for connection with the pipe 2I4 which, in turn, connects to the burner control 18.

The valve 288 also. has riveted to it on the wall 288 a spring member 248. This spring member is tensioned by a cupwhich is riveted to a member 258. This member 258 is connected to a mushroom-shaped diaphragm seal 252 which makes a sealing connection to a bushing 254 in the closing plate 258. This'closing plate 258 is fastenedto the valve body 228 bythe screws 258. Threaded into the bushing 254 is a threaded ad-' justing-sleeve 288 having a knurled end portion 282. This adjusting sleeve 288 is held'in place by a locking member 284 which is provided with a shoulder 288 which looks withv a complementary shoulder upon the threaded bushing 254. The locking member 284 is also threaded onto the adjusting sleeve 288, but is normally locked to it by the clamping screw 288. Thus, this arrange ment normally prevents the rotation of the adjusting sleeve 288. In order to adjust the sleeve 288, it is necessary to loosen the clamping screw 288 and to turn the sleeve 288 by employing the knurled end 282. r v

The adjusting sleeve 288 carries a bracket 218, which is provided with a spring latch in the form of a leaf spring 212 which has its end portion adapted to fit into the notch 214 in therod 218 when it is desired to defrost the secondary evaporating means 84. This is done by pushing the head 218 of the rod 218 inwardly until the spring latch 212 engages the notch 214. This laces the inner end of the rod 218 in engagement with themember 258, thus appl additional spring pressure onto the valve 288 tending to keep the valve in closed position. When the temperature of. the evaporating means 84 becomes sufliciently high, there will\be sufllcient gas pressure in the bellows 288 to force the valve 288 to open position and to force the rod 216 outwardly by forcing the spring latch 212 out or the notch The notch is'provided with a cam surface so that the spring latch 212 may be forced out of the notch by suflicient axial force upon the rod 216. The spring latch 212 may have its tension adjusted by the adjusting screw 288. The sleeve 268 provides an adjustment by which the temperature at which the valve is forced open may be adjusted. The temperature normally kept in the compartment 36 and in the evaporating means 34 is adjusted by adjusting the screw plug 228.

The swinging burner control Referring now more particularly to Figs. 2 and 3, for the details of the burner controlling device, the housing 18 is provided with the plugs I84 and 84 which connect to the capillary tubing I88 and 88 which, in turn, connect to the thermostat bulbs I16 and I6. The plug I84 has the open end of the bellows I86 connected to it, while the plug 84 has the open end of the bellows 88 connected to it. The bellows I86 has its end' closed by a plug I88, while the bellows 86 has its end closed by a plug 88. The plug I88 receives a conically pointed screw I88, while the plug 88 receives the conically pointed screw 98. These screws 88 and I98 are guided by a U-shaped bracket 382 and bear upon opposite sides of the web portion 884 of a primary lever 386 which is pivoted upon the pivot pin 388. This primary lever 386 carries the knife edge of a secondary lever 3I8 which has its opposite end connected to a tension toggle spring 3I2 which, in turn, is connected to an arm 3 extending from a bracket 3l6, also pivoted upon the pin 388. This bracket 3I6 in turn is connected to another bracket 3I8 which, in turn, connects to the burner tube 68.

This burner tube 68 is in the form of an elbow having its outlet 322 at its upper end and its inlet 324 at its lower horizontal end. This lower horizontal end is exactly in alignment with the pivot pin 388. This horizontal inlet portion 324 is provided with a venturi and mixing mouth 328, as is common for gas burners which is fed by the pipe 2I4 which extends from the throttling valve 2I8. This pipe 2 at the portion entering the venturi and mixing portion of v the burner is in exact alignment with the pivot pin 388. Thus, no joint is required between this connecting portion of the pipe 2 and the burner 824. This burner 324 is generally of the Bunsen type and projects a flame into the heating ilues 58 and I56.

As shown in Figs. 1, 2 and 3, the burner 68 is in position to heat the heating flue 56 and the generator 82. The double toggle snap acting device provided by the primary lever 386, the secondary lever 3I8 and the toggle spring 8I2 holds the burner tube 68 in this position until the thermostat 16 becomes sufllciently hot to overcome the force of the toggle mechanism. This occurs only when the generator 82 is substantially exhausted of refrigerant. At this time,- the bellows 88 will contain gas at sufficient pressure to overcome the toggle mechanism and will expand to move the toggle mechanism across dead center, thus moving the burner tube "68 from the position at which it heats the fine 56 to the dotted line position in which it heats the flue I56. The top of the casing I8 is provided with set screws 338 and 382 for stopping the burner tube in each of its extreme positions.

While the form of embodiment of the invention as herein disclosed, constitutes a preferred form,

be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. Absorption refrigerating apparatus including evaporating means, a plurality of generating means, and a condensing means connected between each of said generating means and the evaporating means; means for alternately heating said generating means, said generating means being charged with a liquid absorbent, and means for transferring liquid absorbent from the generating means being heated to the generating means being cooled.

2. Absorption refrigerating apparatus including evaporating means, a plurality of generating means, and a condensing means connected between each of said generating means and the evaporating means; means for alternately heating said generating means, said generating means being charged with a liquid absorbent; means for conducting weak liquor from the generating means being heated to the condensing means connected to the second generating means for absorbing refrigerant from the evaporating means.

3. Absorption refrigerating apparatus including evaporating means, a plurality of generating means, and a condensing means connected between each of said generating means and the evaporating means; means for alternately heating said generating means, said generating means being charged with a liquid absorbent; means for conducting weak liquor from the generating means being heated to the condensing means connected to the second generating means for absorbing refrigerant from the evaporating means, and means for conducting the thus enriched weak liquor from said condensing means to said second generating means.

4. Absorption refrigerating apparatus including an evaporating means, a plurality of condensing means having their lower ends each connected to said evaporating means, a plurality of generating means containing a liquid absorbent, vapor conducting means connecting each of said generating means to the upper portion of one of the condensing means for supplying refrigerant in vapor form, liquid conducting means for connecting the lower end of each condensing means to its generating means, means for conducting weak liquor from each of said generating means to the upper portion of the condensing means connected to the other generating means, and means for alternately heating said generators.

5. Absorption refrigerating apparatus including evaporating means, a plurality of generating means, and a condensing means connected between each of said generating means and the evaporating means; means for alternately heatmg said generating means, said generating means being charged with a liquid absorbent,

and means for transferring liquid absorbent from the generating means being heated to the generating means being cooled; said generating means including a reservoir portion, a heating portion, and a heat transfer portion between said reservoir portion and the heating portion, said heat transfer portion providing a heat exchange between the liquid absorbent and the refrigerant separated from the liquid absorbent.

6. Absorption refrigerating apparatus including evaporating means, a plurality of generating means, and a plurality of heat transfer means, means for alternately heating the generating it is to be undertsood that other forms might means and condensing the refrigerant in'one of the heat transfer means, means for \conducting weak liquor from the generating means being heated t .another of said heat transfer means, and means for conducting evaporated refrigerant from said evaporating means to said another heat transfer means.

'7. Absorption refrigerating apparatus comprising evaporating means divided into two portions by a throttling means, said two portions being substantially thermally isolated, a plurality of heat transfer units connected to the evaporating means, a plurality of generating means connected to said heat transfer units, means for alternately heating said generating means, a compartment to be cooled, a single common secondary volatile liquid system for cooling said compartment including a cooling unit in heat exchange relation with said compartment, said cooling unit containing a volatile liquid, said single common v secondary system having, a portion located above the level of liquid in the secondary system extending into heat exchange relation with both portions of said evaporating means.

8. Absorption refrigerating apparatus comprising two parts, each including means for generating, absorbing, and condensing refrigerant, evaporating means connected between the means of said two parts, said parts containing liquid absorbent and refrigerant, means for conducting liquid absorbent from one part to another, said conducting means including restrlctor means for regulating the flow of liquid absorbent.

9. Absorption refrigerating apparatus comprising two parts, each including means for generating, absorbing, and condensing refrigerant, evaporating means connected between the means of said two parts, said parts containing liquid absorbent and refrigerant, means for conducting liquid absorbent from one part to another, said conducting means including restrictor means for regulating the flow of liquid absorbent, and restrictor means for regulating the flow of refrigerant from one part to another.

10. Absorption refrigerating apparatus comprising two parts, each including means for genmeans for regulating the flow of liquid absorbent in opposite directions. a ll. Absorption refrigerating apparatus comprising two parts, each including means for generating, absorbing, condensing, and evaporating refrigerant; said parts containing liquid absorbprising two parts, each including generating and l absorber-condenser means, evaporating means connected between the means of said two parts, said parts containing liquid absorbent and refrigerant, means for conducting liquid absorbent erating, absorbing, and condensing refrigerant,

evaporating means connected between the means of said two parts, said parts containing liquid absorbent and refrigerant, means for conducting liquid absorbent from one part to anothen'said ---conducting means including separate restrictor from one part to another, said conducting means including restrictor" means for regulating the flow of liquid absorbent, and restrictor means for regulating the flow of refrigerant from one part to another.

l4. Absorption refrigerating apparatus com-' prising two parts, each including generating and absorber-condenser means, evaporating means connected between the means of said two parts, said parts containing liquid absorbent and refrigerant, means for conducting liquid absorbent from one part to another, said conducting means including separate restrictor means for regulating the flow of liquid absorbent in opposite directions.

15. Absorption refrigerating apparatus comprising two parts, each including generator, absorber-condenser means, and evaporating means; said parts containing liquid absorbent and refrigerant, means for conducting liquid absorbent from one part to another, said conducting means including restrictor meansfor regulating the flow of liquid absorbent, and restrictor means for conducting refrigerant between .the two parts.

DON E. DASHER. 

